RU2258095C1 - Method of alumino-thermal production of ferro-niobium - Google Patents

Abstract

FIELD: metallurgy; method of alumino-thermal production of ferro-niobium.

SUBSTANCE: proposed method includes stage-by-stage loading and melting of charge containing niobium concentrate, sodium nitrate, lime, iron ore, aluminum and drainage products of melt; used as niobium concentrate is commercial niobium concentrate. At first stage, charge is loaded at rate of 300-380 kg/m²/min; this charge contains total mass of commercial niobium concentrate and sodium nitrate, 30-70% of iron ore of mass of melt, 20-80% of lime of mass of melt and aluminum in the amount of 0.85-0.99 of amount stoichiometrically required for reduction of elements of ferro-niobium alloy; at second stage, charge is loaded in the amount of 35-55% of mass of niobium pentoxide in commercial niobium concentrate of first stage at rate of 210-270 kg/m²/min, 30-70% of iron ore of mass of melt, 20-80% of lime of mass of melt and aluminum in the amount of 1.6-2.0 of amount stiochiometrically required for reduction of elements of ferro-niobium alloy; before draining, melt is held during period equal to 0.1-0.6 of charge melting time.

EFFECT: increased extraction; improved quality of ferro-niobium alloy.

3 cl, 1 tbl, 9 ex

Description

The invention relates to a method for aluminothermally producing ferroniobium, comprising the stepwise loading and melting of a mixture containing niobium concentrate, iron ore, sodium nitrate, aluminum, and the smelting of melt products.

The invention:

1. In the first stage, load the mixture at a speed of 300-380 kg / m ² · min, containing the entire mass of marketable niobium concentrate and sodium nitrate, 30-70% of iron ore by weight of the smelting, 20-80% of lime by weight of the smelting, and aluminum in the amount of 0.85-0.99 from stoichiometrically necessary for the restoration of ferroniobium alloy elements.

In the second stage, the charge is loaded in an amount of 35-55% by weight of niobium pentoxide in the first stage niobium concentrate at a speed of 210-270 kg / m ² · min, 30-70% of iron ore by weight of smelting, 20-80% of lime by weight melting and aluminum in an amount of 1.6-2.0 from the stoichiometrically necessary to restore the elements of the ferroniobium alloy, and before draining the melt is exposed to 0.1-0.6 charge melting times.

2. When using in the composition of the charge, commodity niobium concentrate with associated niobium concentrate with a content of niobium pentoxide 30-32%, melting is carried out in three stages.

In the first stage, charge the mixture at a speed of 210-280 kg / m ² · min, containing the entire mass of associated niobium concentrate, 10-30% sodium nitrate by weight of the smelting, 20-80% lime by weight of the smelting, and aluminum 0.8-0, 92 from stoichiometrically necessary for the restoration of ferroniobium alloy elements.

In the second stage, load the mixture at a speed of 300-380 kg / m ² · min, containing the entire mass of marketable niobium concentrate, 70-90% sodium nitrate by weight of the smelting, and aluminum in the amount of 0.85-0.99 of the stoichiometrically necessary for recovery Ferroniobium alloy elements.

In the third stage, load the mixture at a speed of 230-240 kg / m ² · min, containing 30-70% of iron ore by weight of smelting, 20-80% of lime by weight of smelting and aluminum in an amount of 1.6-2.0 of stoichiometrically necessary to restore the elements of the ferroniobium alloy and before discharge carry out the exposure of the melt 0.1-0.6 time of melting of the charge.

The invention relates to metallurgy, and specifically to a method for aluminothermic production of ferroniobium.

A known method of aluminothermic production of low-silicon ferroniobium from technical niobium pentoxide, which consists in the stage-by-stage loading and melting of the charge components.

At the first stage, a charge of the composition is loaded: iron ore 560 kg, lime 170 kg and aluminum 140 kg, which is 0.75 of the stoichiometrically necessary for the restoration of elements of the ferroniobium alloy.

At the second stage, a charge of the composition is loaded: niobium pentoxide 1200 kg and aluminum 475 kg, which is 1.12 of the stoichiometrically necessary for the restoration of elements of the ferroniobium alloy.

At the third stage, a charge of the composition was loaded: iron ore 205 kg, lime 170 kg and aluminum 73 kg, which is 1.01 of the stoichiometrically necessary for the restoration of elements of the ferroniobium alloy.

The disadvantage of this method: when used in the smelting of niobium pentoxide, the extraction of niobium in the metal is not more than 92-93.5%. This is due to the fact that in the second stage, aluminothermic reduction reactions of niobium occur in the absence of iron oxides in the charge with the formation of a refractory alloy and worsening conditions for the recovery reactions. At the third stage, a charge was melted with a low specific heat of the process (16 kcal / g-atom) and a lack of aluminum for additional reduction of residual niobium oxides in the slag melt.

The closest technical solution to the invention is a method of aluminothermic production of ferroniobium from commodity niobium concentrates (prototype), which includes stage loading and melting of the charge and draining the melt of the melting products.

At the first stage, a charge is loaded with a loading speed of 430 kg / m ² min, consisting of components from the total mass for melting: iron ore 51%, lime 67% and aluminum in an amount of 1.0 from stoichiometrically necessary for the restoration of elements of the ferroniobium alloy.

In the second stage, the charge is loaded at a rate of 130 kg / m ² min, containing the entire mass of salable niobium concentrate and sodium nitrate and aluminum in an amount of 1.0 from the stoichiometrically necessary to restore the elements of the ferroniobium alloy.

In the third stage, the rest of the iron ore, lime and aluminum are charged in an amount of 1.59 from the stoichiometrically necessary to restore the elements of the ferroniobium alloy with a charge loading speed of 400 kg / m ² min.

The disadvantage of this method: low extraction of niobium in the metal 85-85.5% and increased wear of the magnesite lining of the smelter. This is due to the fact that in the second stage, a low-thermal niobium-containing mixture with a low loading speed and increased heat loss was melted to produce a refractory niobium alloy, which reduces the thermal conditions of the smelting reduction processes.

The melting of the charge in the first and third stages of melting with high thermal conductivity, accompanied by emissions, and the slow melting of the charge in the second stage increase the escape and burn of the charge components. Melting with a high thermal charge in the first stage of melting leads to overheating of the resulting alloy, which destroys the lining of the hearth.

The technical result of this invention is to increase the extraction of niobium in the metal and improving the quality of the alloy. The technical result is achieved by the proposed method of aluminothermic production of ferroniobium, which includes the step-by-step loading and melting of a mixture containing niobium concentrate, sodium nitrate, lime, iron ore, aluminum and the discharge of melt of melting products:

1. A commercial niobium concentrate is used as a niobium concentrate. At the first stage, a charge is loaded at a speed of 300-380 kg / m ² min, containing the entire mass of marketable niobium concentrate and sodium nitrate, 30-70% of iron ore by weight of the smelting, 20-80% of lime by weight of the smelting and aluminum in an amount of 0, 85-0.99 from stoichiometrically necessary for the restoration of ferroniobium alloy elements.

In the second stage, the charge is loaded in an amount of 35-55% by weight of niobium pentoxide in marketable niobium concentrate in the first stage at a speed of 210-270 kg / m ² min, 30-70% of iron ore by weight of smelting, 20-80% of lime by weight melting and aluminum in an amount of 1.6-2.0 from the stoichiomerically necessary for the restoration of the elements of the ferroniobium alloy, and before the discharge carry out the exposure of the melt 0.1-0.6 time of melting of the charge.

2. When using commodity niobium concentrate with associated niobium concentrate in the charge, melting is carried out in three stages:

At the first stage, a charge is loaded at a speed of 210-280 kg / m ² min, containing the entire mass of associated niobium concentrate, 10-30% sodium nitrate by weight of the smelting, 20-80% lime from the weight of the smelting, and aluminum 0.8-0.92 from stoichiometrically necessary to the restoration of ferroniobium alloy elements.

In the second stage, charge the mixture at a speed of 300-380 kg / m ² min, containing the entire mass of salable niobium concentrate, 70-90% sodium nitrate by weight of the smelting, 30-70% of iron ore by weight of the smelting, and aluminum in an amount of 0.85- 0.99 from stoichiometrically necessary for the restoration of elements of a ferroniobium alloy.

In the third stage, load the mixture at a speed of 230-240 kg / m ² min, containing 30-70% of iron ore by weight of smelting, 20-80% by weight of smelting and aluminum in an amount of 1.6-2.0 of the stoichiometrically necessary for recovery elements of a ferroniobium alloy, and before discharge, melt is exposed to 0.1-0.6 charge melting times.

Example 1 (prototype)

Smelting of ferroniobium by an extra-furnace aluminothermic method was carried out under industrial conditions.

In the melting furnace, stepwise loading and melting of the charge were carried out, followed by the discharge of the melt of the melting products.

At the first stage, a charge of composition was loaded and melted: iron ore 185 kg, lime 20 kg and aluminum 60 kg with a charge loading speed of 450 kg / m ² min.

At the second stage, a charge of composition was loaded and melted: salable niobium concentrate 1000 kg, sodium nitrate 115 kg and aluminum 305 kg with a charge loading speed of 120 kg / m ² min.

At the third stage, a charge of iron ore composition 180 kg, lime 10 kg and aluminum 100 kg with a charge loading speed of 400 kg / m ² min was loaded and melted.

The melting of the charge in the first and third stages proceeded violently with emissions of the melt; in the second stage, the melting of the niobium-containing mixture proceeded slowly. The recovery of niobium in the heat was 85.15%.

The proposed method of aluminothermic production of ferroniobium is tested under industrial conditions according to the described technology. The results of swimming trunks of the known method (example 1) and the proposed (examples 2-9) are shown in table 1.

Example 2

In the melting furnace, stepwise loading and melting of the charge were carried out, followed by the discharge of the melt of the melting products.

At the first stage, a charge of composition was loaded and melted: salable niobium concentrate 1000 kg, iron ore 210 kg, sodium nitrate 120 kg and aluminum 345 kg with a charge loading speed of 320 kg / m ² min.

At the second stage of melting, a mixture of composition was loaded and melted: iron ore 170 kg, lime 40 kg and aluminum 115 kg with a charge loading speed of 215 kg / m ² min., The melt was held in the smelting furnace for 3 minutes and then the melt was melted. A further increase in aluminum in the second stage of smelting is impractical, since the thermal melting of the charge decreases and a significant part of the aluminum passes into the metal without participating in the reactions of reduction of niobium oxides in the slag melt. Extraction of niobium in the metal was 92.3%.

Example 3

A charge was gradually loaded and melted into the melting furnace, followed by discharge of the melt of the melting products.

At the first stage, a charge of composition was loaded and melted: salable niobium concentrate 1000 kg, iron ore 240 kg, lime 15 kg, sodium nitrate 120 kg and aluminum 385 kg with a charge loading speed of 350 kg / m ² min.

At the second stage, a charge of composition was loaded and melted: iron ore 140 kg, lime 30 kg and aluminum 85 kg with a charge loading speed of 240 kg / m ² min. After 3 minutes of holding the melt in the smelter, the melt of the melting products was drained. Extraction of niobium in the alloy was 94.7%. A further increase in aluminum in the first stage of melting increases the transition of silicon and titanium into the alloy, reducing its quality.

Example 4

A charge was gradually loaded and melted into the melting furnace, followed by discharge of the melt of the melting products.

At the first stage, a mixture of composition was loaded and melted: salable niobium concentrate 1040 kg, iron ore 226 kg, lime 20 kg, sodium nitrate 125 kg and aluminum 385 kg with a charge loading speed of 350 kg / m ² min.

At the second stage, a charge of composition was loaded and melted: iron ore 170 kg, lime 40 kg and aluminum 105 kg with a loading speed of 250 kg / m ² min. After 3.5 minutes of holding the melt in the smelter, the melt of the melting products was drained. Melting niobium recovery was 95.1%.

Example 5

A charge was gradually loaded and melted into the melting furnace, followed by discharge of the melt of the melting products.

At the first stage, a mixture of composition was loaded and melted: salable niobium concentrate 1000 kg, iron ore 215 kg, lime 10 kg, sodium nitrate 120 kg and aluminum 368 kg with a charge loading speed of 360 kg / m ² min.

At the second stage, a mixture of composition was loaded and melted: iron ore 165 kg, lime 30 kg and aluminum in an amount of 102 kg with a charge loading speed of 245 kg / m ² min. After 3.5 minutes of holding the melt in the smelter, the melt of the melting products was drained. Extraction of niobium in the alloy was 94.9%.

Swimming trunks (examples 2-5) proceeded calmly at all stages. After melting of the charge on the surface of the melt in the smelter, Kip was observed as a result of the deep reduction of niobium oxides in the slag melt. On all heats obtained standard low-silica ferroniobium grade FNB 58 (F).

Extraction of niobium in the alloy was 92.3-95.1%.

When smelting ferroniobium, the associated niobium concentrate and commercial niobium concentrate were used as a part of the charge.

Example 6

In the melting furnace, stepwise loading and melting of the charge were carried out, followed by the discharge of the melt of the melting products.

At the first stage, a charge of composition was loaded and melted: associated niobium concentrate 480 kg, lime 75 kg, sodium nitrate 30 kg and aluminum 160 kg with a charge loading speed of 240 kg / m ² min.

At the second stage, a mixture of composition was loaded and melted: salable niobium concentrate 720 kg, iron ore 65 kg, sodium nitrate 90 kg and aluminum 247 kg with a charge loading speed of 330 kg / m ² min.

In the third stage, a charge of composition was loaded and melted: iron ore 120 kg, lime 25 kg and aluminum 73 kg with a charge loading speed of 240 kg / m ² min.

After 4 minutes of holding the melt in the smelter, the melt of the melting products was drained. The recovery of niobium in the heat was 93%. A further increase in the mass of the associated niobium concentrate in the charge reduces the niobium content and increases the content of silicon and titanium in the metal, which reduces the quality of the alloy.

Example 7

A charge was gradually loaded and melted into the melting furnace, followed by discharge of the melt of the melting products.

At the first stage, a charge of composition was loaded and melted: associated niobium concentrate 240 kg, lime 50 kg, sodium nitrate 16 kg and aluminum in an amount of 80 kg with a charge loading speed of 215 kg / m ² min.

At the second stage, a mixture of composition was loaded and melted: salable niobium concentrate 960 kg, iron ore 93 kg, sodium nitrate 109 kg and aluminum 303 kg with a charge loading speed of 325 kg / m ² min.

At the third stage, a charge of composition was loaded and melted: iron ore 150 kg, lime 40 kg and aluminum 92 kg with a charge loading speed of 240 kg / m ² min.

After 3.7 minutes of holding the melt in the smelter, the melt of the melting products was drained. Extraction of niobium in the metal was 94.9%. A further decrease in the associated niobium-containing product in the charge reduces the economic feasibility of its use.

Example 8

In the melting furnace the charge was loaded and melted, followed by the discharge of the melt of the melting products.

At the first stage, a charge of composition was loaded and melted: associated niobium concentrate 400 kg, lime 70 kg, sodium nitrate 26 kg and aluminum 135 kg with a charge loading speed of 240 kg / m ² min.

At the second stage, a charge of composition was loaded and melted: salable niobium concentrate 800 kg, iron ore 120 kg, sodium nitrate 94 kg and aluminum 280 kg with a charge loading speed of 345 kg / m ² min.

At the third stage, a charge of composition was loaded and melted: iron ore 120 kg, lime 35 kg and aluminum 73 kg with a charge loading speed of 230 kg / m ² min.

After 4 minutes of holding the melt in the smelter, the melt of the melting products was drained. Extraction of niobium in the metal was 94.9%.

Example 9

In the melting furnace the charge was loaded and melted, followed by the discharge of the melt of the melting products.

At the first stage, a charge of composition was loaded and melted: associated niobium concentrate 430 kg, lime 60 kg, sodium nitrate 28 kg and aluminum 145 kg with a charge loading speed of 220 kg / m ² min.

At the second stage, a charge of composition was loaded and melted: salable niobium concentrate 770 kg, iron ore 125 kg, sodium nitrate 97 kg and aluminum 270 kg with a charge loading speed of 345 kg / m ² min.

At the third stage, a mixture of composition was loaded and melted: iron ore 115 kg, lime 25 kg and aluminum 70 kg with a charge loading speed of 240 kg / m ² min.

After 3 minutes of holding the melt in the smelter, the melt of the melting products was drained. Extraction of niobium in the metal was 94.5%.

Swimming trunks (examples 6-9) proceeded calmly. After the charge was melted in the third stage, “Kip” was observed on the melt surface in the furnace for 3-4 minutes, as a result of the deep reduction of residual niobium oxides in the slag melt. The standard low-silica ferroniobium grade FNB 58 (F) was obtained.

Extraction of niobium in swimming trunks was 93-94.9%.

The technological difference of the proposed method from the known one lies in the fact that in the niobium-containing parts of the charge there is a joint reduction of niobium and iron oxides, which improves the conditions for the reduction of niobium. The melting of a niobium-containing charge with an amount of aluminum of 0.8-0.99 from the stoichiometrically necessary for the reduction of elements of the ferroniobium alloy reduces the transition of silicon and titanium into the alloy, while silicon oxides bind to the calcium oxides present in the charge, forming a strong compound. Melting at the first stage of the associated niobium concentrate occurs with the formation of a low-melting iron-niobium alloy, which does not destroy the lining of the smelter and facilitates the further course of niobium reduction processes.

The rational distribution of the charge components in the indicated ratios over the melting stages provides the optimal specific heat of the process 19-20 kcal / g-atom and a high melting rate of the charge with minimal heat loss, which is crucial for maintaining the optimum temperature of aluminothermic melting of ferroniobium and conditions for the reduction of niobium, as well as increasing conditions for the efficient use of aluminum at the stage of melting of a niobium-containing mixture due to the excessive concentration of reduced oxides in terms of ju to the reducing agent, at the last stage due to the deep reduction of niobium oxides in the slag melt.

According to the proposed method for the extraction of niobium in the metal was 92.3-95.1%, which is 7.2-10% higher than the extraction according to the known method.

The use of commercially available niobium concentrate and non-standard niobium concentrate in the mixture of aluminothermic smelting ensures the production of low-silicon ferroniobium grade FNB 58 (F).

Table number 1. Examples Charge parts Commodity niobium concentrate Associated niobium concentrate The average content of Nb ₂ O ₅ in the mixture,% Chemical composition Chemical composition Iron ore Nb ₂ O ₅
SiO ₂
TiO ₂
Fe ₂ About ₃
Cao
S
P 62-63%
2.5-3.0%
2.0-3.0%
2-3%
12-14%
0.008-0.01%
0.25-0.30% Nb ₂ 0 ₅
SiO ₂
TiO ₂
Fe ₂ O ₃
S
P 30-32%
4-5%
12-15%
44-46.0%
0.02%
0.25-0.30% Kg % Kg % % Kg % 1 2 3 4 5 6 7 8 nine Example 1 (prototype) one
2
3 -
1000
- -
100.0
- - - 63.3 185
-
180 50.7
-
49.3 Example 2 one
2 1000
- 100.0
- - - 62.47 210 170 55.3
44.7 Example 3 one
2 1000
- 100.0
- - - 62,2 240 140 63.0
37.0 Example 4 one
2 1040
- 100.0
- - - 62.0 226 170 57.0
43.0 Example 5 one
2 1000
- 100.0
- - - 62.64 215 165 56.0
44.0 Example 6 one
2
3
720
-
60.0
- 480
-
- 40
-
- 49.9 -
65
120
35.0
65.0 Example 7 one
2
3 -
960
- -
80.0
- 240
- 20,0
- 56.0 -
93
150
38.3
61.7 Example 8 one
2
3 -
800
- -
66.7
- 400
-
- 33.3
-
- 51.3 -
120 120
50,0
50,0 Example 9 one
2
3 -
770
- -
64.1
- 430
-
- 35.8
-
- 51,2 -
125 115
52.0
48.0

Continuation of table number 1. Oxidizing agent Metal weight Extraction of niobium,% The degree of use of aluminum,% The charge loading rate kg / m ² min Lime Sodium Nitrate Aluminum 99% of stoichiometrically necessary Physical weight Base weight Kg % Kg % Kg % Kg Kg 10 eleven 12 thirteen 14 fifteen 16 17 eighteen 19 twenty twenty
-
10 67.0
-
33.0 -
115
- -
100.0
- 60
305,100 100.0 100.0
160,0 686.0 754.6 85.15 97.0 430 130 400 -
40 -
100.0 120
- 100.0
- 345
115 88.4
200,0 720 807.5 92.3 98.3 430
215 fifteen
thirty 33.0 67.0 120 100.0 385
85 98.9
180.0 710 824.8 94.7 98.6 350
240 twenty
40 33.0 67.0 125
- 100.0
- 385
105 96.7
174.0 745.2 858.5 95.1 98.4 350
250 10
thirty 25.0 75.0 120
- 100.0
- 368 102 95.1
183.0 715 832.3 94.9 98.5 360
245 75
-
25 75.0
-
25.0 thirty
90
- 25.0 75.0
- 160,247
73 88.5
95.7
80.5 726.0 779.7 93.0 98.5 240
330
240 fifty
-
40 55.0
-
45.0 16
109
- 13.0 87.0
- 80
303
92 89.0
95.05
182.0 757.0 880.4 97g9 98.3 215
325
240 70
-
35 66.7
-
33.3 26
94
- 21.7 78.3
- 135
280
73 87.8
89.8
179.2 725.0 816.4 94.9 98.4 240
345
230 60
-
25 70.0
-
30,0 28
97 22.4 77.6 145,270
70 88.3
95.5
182 735.0 812.9 94.5 98.4 220
345
240

Continuation of table No. 1. The chemical composition of the metal,% Alloy grade The content of Nb ₂ O ₅ in the slag Thermal charge, kcal / gr.at. Process characteristics Nb Si Al Ti FROM S R 21 22 23 24 25 26 27 28 29th thirty 31 55.0 2.0 2,4 1,0 0.02 0.01 0.40 NWF 58 (F) 5.8 25.5
16,4
22.3 Flowing violently with emissions
Flowing slowly
Flowing violently with emissions 56.06 1.7 1,1 0.55 0.01 0.006 0.40 NWF 58 (F) 2,3 19.3
18.1 Flowing quietly 58.08 2.0 0.9 2.0 0.02 0.005 0.38 NWF 58 (F) 1,5 19.3
19.0 Flowing quietly 57.6 1.96 1,0 1.9 0,029 0,03 0.40 NWF 58 (F) 1.41 19.6
19,2 Flowing quietly 58.2 1.9 0.95 1,0 0.02 0.008 0.39 NWF 58 (F) 1.4 19.3
19.0 Flowing quietly 53.7 2.01 0.98 2.0 0,03 0,03 0.40 FPB 58 (F) 1.38 20,0
19.0
19.1 Flowing quietly 58.55 1.98 1,1 1,6 0.04 0.009 0.40 FIB 58 (F) 1.4 18.6
19.0
19.0 Flowing quietly 56.3 1.8 1.05 1.7 0,035 0.009 0.38 NWF 58 (F) 1.28 19.8
19,2
18.8 Flowing quietly 55.3 1.97 1.06 1.71 0.008 0.008 0.39 NWF 58 (F) 1.3 18.9
19,4
18.9 Flowing quietly

Claims (2)

1. A method for aluminothermally producing ferroniobium, comprising the stepwise loading and smelting of a mixture containing niobium concentrate, sodium nitrate, lime, iron ore, aluminum, and melting of the melt products, characterized in that commodity niobium concentrate is used as the niobium concentrate in the first stage load the mixture at a speed of 300-380 kg / (m ² · min) containing the entire mass of salable niobium concentrate and sodium nitrate, 30-70% of iron ore by weight of smelting, 20-80% of lime by weight of smelting and aluminum in quantity 0.85-0.99 stoichiometrically necessary for the restoration of ferroniobium alloy elements, in the second stage, a charge is charged in an amount of 35-55% by weight of niobium pentoxide in the first stage niobium concentrate at a speed of 210-270 kg / (m ² · min) , 30-70% of iron ore by weight of smelting, 20-80% of lime by weight of smelting, and aluminum in an amount of 1.6-2.0 stoichiometrically necessary for the recovery of elements of the ferroniobium alloy and before the discharge carry out the exposure of the melt 0.1-0.6 charge penetration time. 2. A method for aluminothermally producing ferroniobium, comprising the stepwise loading and smelting of a mixture containing niobium concentrate, sodium nitrate, lime, iron ore, aluminum, and smelting of the melt of the melting products, characterized in that commodity niobium concentrate with associated niobium concentrate is used as niobium concentrate niobium pentoxide with a content of 30-32%, in the first step is charged with the charge rate of 210-280 kg / (m ² · min) containing the entire mass associated niobium concentrate, 10-30% by weight of sodium nitrate melting, 20-80% lime by weight and the melting aluminum in a range 0,8-0,92 stoichiometrically required for restoration alloy elements ferroniobium, in a second step the charge charged at a rate of 300-380 kg / (m ² · min) containing the entire mass of salable niobium concentrate, 70-90% sodium nitrate by weight of smelting, 30-70% of iron ore by weight of smelting, and aluminum in the amount of 0.85-0.99 stoichiometrically necessary to restore the elements of the ferroniobium alloy, in the third stage, charge the mixture 230-240 kg / (m ² · min) containing 30-70% iron ore from m ssy melting, 20-80% lime by weight and the melting aluminum in an amount of 1.6-2.0 stoichiometrically required for restoration alloy elements ferroniobium and before discharge of the melt is carried 0.1-0.6 exposure time of penetration of the charge.